Longer first line chemotherapy duration has recently been associated with a modest, but significant improvement in overall survival and a clinically meaningful and statistically significant improvement in progression-free survival, in metastatic breast cancer patients. Prolonging chemotherapy until disease progression, however, must be weighed against the detrimental effects of continuous chemotherapy delivery. The SNAP trial seeks to improve the tolerability of prolonged chemotherapy administration strategy by studying alternative treatment schedules, while preserving and possibly improving treatment efficacy in this disease setting.